@Gorgritch_umie_killa @Lodespawn I'm envisaging them leveraging the single-sign-on type stuff they do for MyGov. But do you trust them, and the social site, to handle and appropriately, securely anonymise the Personally Identifiable Information in the transaction? And of course, that means that now under 16s need to have MyGov IDs. The idea of online nicknames etc being linked to actual persons should be a concern. Australia Card anyone?
Of course they may have a completely different approach to it. I mean, every school age child already has a Student Number. That could be a data point for them. Who knows.

@Gorgritch_umie_killa @Lodespawn Doesn't sound too big a technological challenge (think along the lines of when you sign into a website using Google or Facebook as your ID provider). But puts more hassle on site admins. And, more importantly, how are users going to know if a site is actually doing authentication or just gathering their ID data? Then there's the question of what sites they will try and include in the ban. Meta etc is a given, but Lucy's Australian Knitting forum? iMessage? Signal? Mastodon instances?
Then there's the concern that all of a sudden Govt have a link between all of our online nicknames etc and our actual names. That's a massive issue in my eyes and they'll need to clarify if that's going to happen.
In the end my son could, and probably will, just rent a private server in Singapore for a couple of dollars a month and VPN through that. I expect he'll set his mates up on it too. So instead of some kind of visibility of what he's doing on the home network, I'll have none.
And we'll be paying handsomely for this whole exercise.
I, like a lot of parents I'm sure, am actually in favour of not letting kids into those places. But I can't, yet, see how it can be done.

The way I see it it would be a struggle for big social media sites to implement. I think they are more likely to shimmy on out of here.